More than 11,500 health workers and about 40,000 primary school teachers have voted to walk off the job on the same day - and thousands more may join them.
Unions for secondary school teachers, senior doctors and nurses are also considering industrial action.
CTU president Richard Wagstaff said if the unions go ahead with strikes, it would be the biggest walk-off in about 40 years.
He said the CTU 100% backed the unions in advancing their collective agreements.
Health New Zealand has said its offer to allied health workers of a 2% pay rise, followed by a 1.5% increase over a 30-month period, was fair.
Today it said it had not yet received a strike notice from the Public Service Association (PSA) representing allied health workers.
On RNZ's Morning Report programme yesterday, Health Minister Simeon Brown called the strikes "deliberate politicking by our unions".
"It's the unions who are playing politics, it's the union leadership that's playing politics, and the unions are disrupting the care of thousands of patients needing care, disrupting the learning of thousands and thousands of students who are learning in our classrooms.
"They are simply just playing politics."
Unions made a choice to strike instead of sitting down to negotiate, he said.
"Hips, knees, and cataract operations are going to be disrupted - all because of a choice by a union, rather than actually working through the issues with their employers.
"The fact that they're all doing this on same date... this is politics ahead of actually public service, which is what they should be about."
But a mental health social worker and PSA union delegate today hit back at the criticism, claiming the only person "playing politics" was Simeon Brown.
Andy Colwell told Morning Report he was sceptical that the minister understood the challenges the workforce was facing.
"We work in our health service but we also access our health service, and so do our family and friends. We understand what is going on very well ... and we understand what provides quality healthcare.
"I think it's up to the minister to actually either be very informed, or actually care about what is going on in the health sector at the moment - because clearly he doesn't."
Colwell said the strikes were not just about money, but maintaining safe staffing levels. In his line of work, it was important to know that his colleagues would be beside him when he turned up to work.
"It's a complex and difficult job with people who are really distressed and need our support and care.
"Occasionally they become so distressed that they may physically or verbally abuse us - that's part of the job, but we don't go to work to be threatened or punched."
The Nurses Organisation (NZNO) and Association of Salaried Medical Specialists (ASMS) - which includes senior doctors and dentists - have confirmed ballots on whether to take strike action on October 23 are under way.
The NZNO said results would be known by tomorrow afternoon, while the ASMS said it would know next week after voting closes on Monday October 6.
If senior doctors and dentists do vote for industrial action, it would see a four-hour walk off between 11am and 3pm in the main centres Hamilton, Christchurch, Dunedin, Auckland and Wellington.
The Post Primary Teachers' Association said it would confirm next weekend whether its members would be joining the strikes, with voting opening next week.
Bargaining stalls
The PSA said allied health staff voted overwhelmingly for industrial action, after what it described as the failure of Health New Zealand (HNZ) to provide a fair offer since bargaining started in June this year.
"These are critical health workers who see first-hand how the health system is failing New Zealanders every day. They want to see the government fund health services properly, National secretary Fleur Fitzsimons said.
"Health NZ needs to listen to the voice of workers and come back to the bargaining table with an offer that provides for safer staffing levels, ends delays in recruiting new staff, and a better pay offer that reflects their value to the health system."
Fitzsimons said the pay offer was well below inflation.
PSA vice-president Dianna Mancer, an occupational therapist in the Mid-Central region, said she and her colleagues were working over capacity and constantly carrying vacancies.
The current offer did not address the recruitment challenges and retention issues, she said.
"I can't remember the last time as a department that we were fully staffed. We have a high turnover of staff, we are losing younger staff overseas to Australia mainly, or to private practices, or leaving the health workforce."
Meanwhile, the Professional Firefighters Union has announced a one-hour full stoppage strike by paid firefighters between noon and 1pm on October 17.
